1st all grain, can someone check my math? - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > 1st all grain, can someone check my math?

Thread Tools
Old 06-18-2011, 06:27 PM   #1
Mar 2011
Flourtown, PA
Posts: 1,411
Liked 99 Times on 72 Posts


I'm about to do our first AG tomorrow, and would like some clarification. My recipe has 24lbs of grain (pale ale, 10 gallon batch).

My math says (at a rate of 1.25 qts/lb) that I need 7.5 gallons of strike water at 162 degrees, then maintain 154 degrees.
I need 12 gallons of sparge water at 168 degrees. Is this correct?

I have purchased Beersmith, and quite frankly am having a hard time setting it up.

Thanks for any help.

Reply With Quote
Old 06-18-2011, 06:44 PM   #2
BIAB Expert Tailor
wilserbrewer's Avatar
May 2007
Jersey Shore, New Jersey
Posts: 9,593
Liked 1396 Times on 1068 Posts

Just spitballing here...but striking at 162 sounds low to hit a mash of 154. IME I would strike closer to 168 to land at 154. Much easier to strike high and temper down w/ either cool water or a few ice cubes.

As far as gallons of sparge water, i always find it simpler to measure the amount of wort needed on the final sparge, and sparge w/ that amount to reach your intended pre boil volume. Example: It matters none what the calculator says if you need 3.5 gallons more wort...then sparge 3.5 gallons

edit...here is a handy very simple brewing calc...http://www.rackers.org/calcs.shtml

fwiw it shows a strike of 171 for a mash of 154.

Reply With Quote
Old 06-18-2011, 06:47 PM   #3
Oct 2009
Posts: 299
Liked 5 Times on 5 Posts

24lbs x 1.25 = 30qts/4 = 7.5 gallons so yes that is correct

The 1/2 gallon per pound of grain for sparge is not always accurate to me. You'll have to find what works well for your system. Start with a 12 gallons sparge and if you end up with 12 gallons total collection in the BK from your mash and sparge then you can adjust down. Or you can collect all the runnings and lengthen your boil time. I would recommend doing a double sparge. Do a 6 gallon sparge first, stir, rest for 25mins, drain. Do a second sparge amount based on how much of the initial 6 gallons you were able to collect and repeat.

In regards to the mash, 162 is assuming your mash tun is pre heated to at least 154 before you add water and grains. A cold or room temp mash tun will make you miss your mark for sure.

Your sparge water is going to be higher than 168, you want the mash tun to be 168 and you will have to raise the grain bed from 154 to 168.

Reply With Quote
Old 06-18-2011, 09:06 PM   #4
PT Ray
Aug 2005
Posts: 1,373
Liked 7 Times on 7 Posts

162 degree strike water sounds right if you preheat the mash tun and don't have to account for its thermal mass. I've seen brewers over heat the water, pour it in the mash tun and wait for it to drop to the strike temp. For me, 168 degree strike water with a 1.25qt water ratio will get me around a 154 degree mash in without preheating the mash tun.

The way a figure sparge water is a modified 2qt:1lb rule. I use a total of 3qts:1lb for mash and sparge. So if I'm using 1.25qt for mashing, sparge will be 1.75qt:1lb. This rarely gives me enough pre-boil volume and have to add some water to the kettle. But I feel more comfortable that I'm not over sparging.

Reply With Quote
Old 06-23-2011, 06:24 AM   #5
millaj92's Avatar
Nov 2010
Plano, Texas
Posts: 142
Liked 2 Times on 2 Posts

I start out planning to use 1 half gallon of sparge water per pound of grain. I fly sparge until the gravity of the run-off is 1.010. I rarely use all the sparge water and I have yet to drain all the liquid out of the lauter tun.
Talisman Ale Co.
Find your inspiration...

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
All Grain Split Boil Math? iBrewBeer All Grain & Partial Mash Brewing 7 06-10-2011 12:41 AM
Partial Boil - Math Check Please Krrazy All Grain & Partial Mash Brewing 6 04-30-2011 02:19 AM
2nd AG - no mash out batch sparge *CHECK MY MATH* idigg All Grain & Partial Mash Brewing 6 02-03-2011 06:24 PM
Check my PM procedure/math Fat Guy Brewing All Grain & Partial Mash Brewing 1 01-23-2009 03:56 AM
First Planned PM: Please check my Math and Procedures Yin_Yang All Grain & Partial Mash Brewing 9 08-20-2008 01:44 AM

Forum Jump